Tape for slide fasteners



Nov. 2, 1943. wm ss 2,333,352

TAPE FOR SLIDE FASTENERS Filed Dec. 7, 1940 Figl . INVENTOR F g |2 GEORGE W|NTR| ss f ATTORNEYS Patented Nov. 2, 1943 UNITED STATES PATENT OFFECE TAPE FOR SLIDE FASTENERS George Wintriss, Cranford, N. 1., assignor to Conmar Products Corporation, Bayonne, N. .L, a corporation of New Jersey Application December 7, 1940, Serial No. 369,066

11 Claims. (Cl. 139-384) This invention relates to slide fasteners, and more particularly to a beaded tape for use with the same.- Although numerous proposals have heretofore been made for integrally weaving a bead on a tape for the reception of slide fastener elements, such tapes have not proven entirely successful. These tapes have for the most part used a woven sleeve to enclose a cord or stuifing material to form the bead. Such a tape with a single woven bead does not provide as good a hold for the elements as a tape with two beads. However, an integrally woven tape with two fully enclosed beads becomes too bulky. All of these tapes with a woven sleeve are expensive to manuiacture.

Such woven tapes have accordingly been almost universally replaced by the stitching of two separate cords on opposite sides of a flat tape near one edge thereof. The stitching of two cords is, however. not an ideal practice, it having a number of important disadvantages. One is the need for special sewing machines and guides, and the expense of the extra sewing operation. Another is the need for properly adjusting the tension so that the tape will remain straight or will have a slight concavity at the 'bead, the purpose of this being to ultimately obtain a straight tape after the bead has been stretched somewhat by clamping the fastener elements thereon. The slide fastener manufacturer, and this makes it necessary to purchase cords and sewing machine thread of exactly the same color as the tape, the latter being dyed by the tape manufacturer. This color problem is serious because of the vast number of differently colored tapes required for the garment industry. In general, it seems illogical not to form a satisfactory head as a part oi the operation of weaving the tape. sewing operation is commonly performed by the The primary object of the present invention is to generally improve integrally woven tapes. A more particular object is to provide such a tape which will be inexpensive to manufacture, and which will cooperate satisfactorily with the slide fastener elements, it having all of the advantages of the conventional sewed tape without. however, necessitating a separate sewing operation. Still another object is to provide a tape of such design that when dyed, it will shrink to concave configuration such that it will become straight when the fastener elements are attached.

For this purpose, I provide a tape the beaded edge of which is formed by two oppositely twisted cords. I These cords are substantially exposed.

they being held by a loop of weft thread at spaced intervals approximating, say, 1 6 of an inch. Each cord, being twisted, may be stretched during the weaving operation, thus promoting shrinkage.

Protection of the weft loops is another and important object of my invention.

In some cases an increased initial tape concavity may be desired. A further and optionally usable object of the invention is to increase the concavity obtainable by shrinkage.

To the accomplishment of the foregoing and such other objects as will hereinafter appear, my invention consists in the slide fastener tape elements and their relat on one to the other, as hereinafter are more particularly des ribed in the specification and sought to be defined in the claims. The specification is accompanied by a drawing in which:

- Fig. 1 illustrates a tape woven in straight condition;

Fig. 2 illustrates a tape changed to concave configurat on by shrinkage;

Fig. 3 illustrates a slide fastener stringer, and shows how the clamping of the elements on the tape restores the same to straight configurat on;

Fig. 4'15 a fragmentary view of the beaded edge of the tape drawn to enlarged scale and simplified or idealized for clarity:

Fig. 5 is a fragmentary side elevation of the threads;

Fig. '7 is a similar diagram illustrating the next or return passage of the shuttle;

Fig. 8 is a similar diagram illustrating the suc ceeding passage of the shuttle; Fig. 9 is a similar diagram illustrating the next succeeding passage of the shuttle;

Fig. 10 is a diagrammatic cross-sectional view of the tape taken at a position between Figs. 7 and 8, th s view differing from a true cross-section in showing the warp threads lying in a com mon plane at equal spacing;

Fig. 11 is a sect on similar to Fig. 10. but taken at a point following Fig. 9, and shows the weft threads of Fi 8 and 9; and- Fig. 12 is a conventional Weaver's diagram for the tape.

Referring to the drawing, and more particularly to Figs. 1, 2, and 3, the tape i2 is initially woven in straight condition, as is illustrated in Fig. 1. It may, even emerge from the weaving machine slightly convex at the beaded edge l4,

and enough shrinkage may be subsequently provided to overcome the initial convexity and to instead produce a desired concavity at the beaded edge, as is illustrated in Fig. 2. The purpose of this is to anticipate and compensate for some stretch or elongation of the beaded edge caused by clamping the fastener elements I8 thereon. Thus in Fig. 3, the finished slide fastener stringer ll comprising the tape i2 with the fastener elements I 6 clamped on the beaded edge H, has

been restored to straight condition.

Referring now to Figs. 4 and 5, the beaded edge comprises two .twisted cords and 22. These should be twisted in opposite direction, for otherwise the tape will have a tendency to twist or spiral. The particular tape here shown has a herringbone weave, there being twill formations at 24, 28, 28, and 3B. The weave at the marginal or free edge portion 20 may, if desired, be modified as will be subsequently described, in order to produce a closer or tighter weave at this point. While a herringbone weave is shown, the par- Y ticular weave or design selected for thetape is not of particular importance to the invention.

The cord 20 is held in position by' loops 32 of weft thread, while the cord .22 is held in position by loops 24 of weft thread. Warp threads 38 and 88 are located outside of the cords 20 and 22, and help anchor the weft threads in position. Fig. 4 is artificial or idealized in showing the threads 28 and 32 parallel, whereas in practice they are pulled in one direction or the other by the weft thread. It will be noted that the weft loops 32 alternate with or are staggered relative to the weft loops 34. This helps exaggerate the spacing between the weft loops so that the cords are substantially unconfined and may readily expand transversely between the weft loops.

The use of twisted cords facilitates the weaving operation, for only a single cord need be handled to create the entire bead on one sideof the tape. The twist in the cord is desirable not only to facilitate handling the same as a single warp thread, which is in itself important for manufacturing convenience, but also to facilitate stretch of the cord under tension caused by an appropriate size of drop weight, for this stretch tends to encourage subsequent shrinkage. The tighter or shorter the pitch of the twist in the cord, the greater the stretch. and the greater the tendency toward shrinkage. However, it is not desirable to employ. atightly twisted cord because a tighter twist makes the cord harder, and the resulting bead is less satisfactory for attachment of the elements to the tape. It is desirable to keep the cord soft enough so that the Jaws of the elements can embed themselves in the bead when clamped thereagainst, and also so that the loops 22 and 24 tend to embed themselves in the cords.

Control of the diflerential shrinkage may, in some cases, be desired, and in such case can be obtained by introducing extra warp threads at shrinkage. while the free edge is so constructed?! as to discourage shrinkage, and the net result is the production of the desired concave shape.

A conventional weavers diagram for the particular tape weave here illustrated, is. given in Fig. 12. The left-hand end of this diagram is a chain diagram, and indicates the cams, and consequently represents positions of the harnesses or frames, the black squares corresponding to an up position, and the white squares to a down positionjor vice versa. The chains move in the direction of the arrow, and so act in the order of the numerals I, 2, 3, and 4 indicated on the diagram. The nextfour positions simply repeat the first four, and therefore have not been numbered. The balance of the diagram is a harness diagram with a representation of the warp threads. The black squares correspond to the ordinary warp threads. 'The crossed white squares 40 correspond to the extra warp threads at the free edge of the tape. The open white squares 20 and 22 correspond to the twisted cords.

' The arrows 42 represent the reeds through which I the warpthreads pass, and which function to close up the successive weft threads. tice, the reeds 42 are spaced substantially uniformly, and therefore the increased spacing at the left and right ends of the diagram correspond to an increased or relative crowding of the warp threads.

Figs. 6 through 9 represent in a schematic way the actual weaving operation." The weft thread is indicated at 44, and it passes through a space between the warp threads, some of which have been lifted, and others lowered by their respective frames or harnesses. In the body of the tape, the weave is a conventional one-two'weave producing the desired twill appearance. Thread 38 and cord 20 are :up, and thread 22 and cord 22 are down. The shuttle has completed its movement to the left. In Fig. 7 the harnesses have changed, thread 36 and cord 22 being raised, and thread 28 being lowered. The weft thread 46 has therefore passed around the cord 22. In Fig. 8 the shuttle has again completed its movement to the left. The cord 22 has been lowered, and the weft thread ll therefore passes between the cords. In Fig. 9 the thread 38 and cord 20 have been lowered, and thread 28 has been raised, hence the weft thread passes around the cord 20. The next step corresponds to Fig. 6 again,

and at this time the cord 20 has been raised so that the weft thread 44 passes between the cords.

Figs. 10 and 11 are more or less diagrammatic cross-sectional views of the tape, which diifer from Figs. 8 through 9 in bringing the cords 20 and 22 in vertical superposition, which is substantially the position'thcy assume in practice as a result of the pulling of the weft threads: in

bringing the threads ll and B2 closer to the cords: and in bringing the warp threads into a common plane with the weft threads'rising and falling to interweave with the warp threads.

Fig. 10 shows the weft threads 40 and 44 of both Figs. 7 and 8, and Fig. 11 shows the weft threads I. and 4| of both Figs. 9 and 8. The sections of Figs. 10 and 11 are not true cross-sections. because in practice the warp threads rise and fall relative to one another and also to the weft threads. This applies also to the threads SI and 28, which actually bunch up against the cords 20 and 22. However, it would be extremely difiicult to draw a true picture of the thread structure in the tape. The crowding of warp threads 28 and 52 into the cords 20 and 22 keeps the weft loopswrapped closely about the cords. so that In practhey will not be exposed to the action 01 the slider of the slide fastener.

In the specific tape here shown, there are 52 warp threads. This is an unusually large numher for a tape 1 inches in width. The weft thread tension is increased in order to maintain the desired tape width, despite the increased number of warp threads. It is thisarrangement which helps crowd the threads 38 and 52 into the cords, and so to hold the weft loops closely about the cords.

The warp threads are supplied under e1 moderate tension. The cords 20 and 22 are put under higher tension. This increased tension helps produce the desired differential shrinkage when dyeing, because the increased tension causes stretch which in turn encourages subsequent shrinkage. Shrinkage is accompanied by transverse expansion, and shrinkage is inhibited when transverse expansion is prevented. The weave at the free edge of the tape is in contrast with the exposed open condition at the twisted cords, the latter being an ideal condition for shrinkage, and the former tending to prevent shrinkage. There is only a single weft thread, the tension of this being suitably controlled for proper tape width. In the present case the tape is ft: of an inch in width. The cords are preferably #16 Erownell, with a. twist of 5.8 turns per inch, there being four ends of four-ply #20 yarn, that is #20/4/ It will be understood that the specific quantitative dimensions given above are for purposes of illustration, and not in limitation of the invention.

It is believed that the method of weaving my improved tape with integrally woven double beaded edge, as well as the many advantages of the improved tape, will apparent from the foregoing detailed description thereof. also be apparent that while I have shown and tiescribed the invention in a preferred form, changes and modifications may bemade without departing from the spirit of the invention defined in the following claims.

I claim:

1. A tape for receiving the elements of a slide by two relatively large soft cords, one cord being disposed on each side of the tape, the cords being held by loops of weft thread. said tape having a greater number of warp threads than would normally be employed for a given tape width, the weft thread tension being so great as to reducethe tape to said given tape width and to crowd the -warp threads adjacent the cords into the space between the cords in order to hold the loops of weft thread closely about the cords.

2. A tape for receiving the elements of a slide fastener, said tape comprising a woven web having a beaded edge, the beaded edge being formed by two oppositely twisted cords and one or more warp threads located outside of said cords, the cords being held solely by relatively widely spaced loops of weft thread, said tape having a greater number of warp threads than would normally be employed for a given tape width, the weft thread tension being so great as to reduce the tape to said given tape width and to crowd the Warp threads adjacent the cords into the space between the cords in order to hold the loops of weft thread closely about the cords.

It will 3. A tape for receiving the elements of a slide fastener, said tape comprising a woven web having a free edge and a beaded edge, said web having near the tree edge, in comparison with the number oi warp threads in the rest of the web. extra warp threads per loop or weft thread producing a tighter weave in the web at its free edge in order to inhibit shrinkage at the free edge, the beaded edge being so constructed as to encourage shrinkage, whereby said tape is made concave at the beaded edge.

4. A tape for receiving the elements of a slide fastener, said tape comprising a woven web having a free edge and a beaded edge, the beaded edge being formed by two oppositely twisted cords held in position by relatively widely spaced loops of webt thread, said web having near the free edge, in comparison with the number of warp threads in the rest of the web, extra warp threads per loop of weft thread producing a tighter weave in the web at its free edge in order to inhibit shrinkage at the free edge while encouraging shrinkage at the beaded edge, whereby said tape is made concave at the beaded edge an amount sufilcient to result in a suhstan tially straight stringer'when the beaded a "e is subsequently expanded by the clamping of inter lockable fasten-er elements thereon.

5. A tape for receiving the elements of a slide fastener, said tape comprising a woven web haw ing a free edge and a beaded edge, the beaded edge being formed by two cords and one or more warp threads located outside of said cords and acting as a binder for the weft thread, the "t thread running through the web, betweethe cords. to the binder, over on cord, the web, then back through the web, is

the cords, to the binder, under the other o d,

warp threads near the free edge of the 1 producing a relatively tight weave the its free edge in order to inhibit shrin' the free edge while encouraging shrinl g the beaded edge, whereby said tape is co cave at the beaded edge. when shrunlr, by dyeing.

6. A tape for receiving the elements of fastener, said tape comprising a woven we ha" ing a free edge and a beaded edge. the beaded edge being formed by two oppositely twisted or more Warp threads located said cores and acting as a binder the wef the weft thread running thro web, .W the cords, to the binder, ova: one cord, hrough the web, then through the web, between the cords. to the ind er, the other. cord, and through the h, the cords ng only a moderate amount of twist and being somewhat soil; and expanded between the loops of weft thread, said web hav ing extra warp threads near the free edge of the tape producing a relatively tight weave in the web at its free edge in order to inhibit shrin age at the free edge while encouraging shrinkage at the beaded edge, whereby said tape is made concave at the beaded edge when shrunk, a by dyeing.

'1, In the manufacture of woven tape for receivingthe elements or a slide fastener, the method which includes forming a moderately soft beaded edge by laying in two relatively large soft cords near one edge, one cord being laid in on each side of the tape, employing a larger number of warp threads for the tape fabric than outside would normally be employed forthe desired width, weaving said warp threads together by means or a welt thread spaced loops of which function to bind the cords in position, and tensioning said weft thread enough to reduce the tape width to desired amount, whereby the resulting crowding of warp threads between the twisted cords functions to hold the loops or weft thread closely around said cords.

8. In the manufacture of woven tape for receiving the elements oi. a slide fastener, the method which includes forming a. moderately soft beaded edge by laying in two oppositely twisted cords as warp threads near one edge, one cord being laid in on each side of the tape, employing a larger number of warp threads for the tape fabric than would normally be employed for the desired width, weaving said warp threads together by means of a weft thread alternate spaced loops of which function to bind the cords in position, and tensioning said weft thread enough to reduce the tape width to desired amount, whereby the resulting crowding of warp threads between the twisted cords functions to hold the loops of weit thread closely around said cords.

9. In the manufacture of woven tape for receiving the elements of a slide fastener, the method which includes forming a shrinkable beaded edge, laying extra warp threads in the web of tape near the free edge thereof to pro duce a tight weave at the free edge in order to inhibit shrinkage at the free edge, and thereafter appropriately dyeing the tape and thereby differentially shrinking the same so as to make the same concave at the beaded edge.

10. In the manufacture of woven tape for recelving the elements of a. slide fastener, the method which includes forming a moderately soft beaded edge by laying in two oppositely twisted cords as warp threads adjacent one edge, one cord being laid in on each side of the tape, binding said cords in'position by means of a single weft thread, laying extra warp threads in the webof tape near, the free edge thereof to produce a tight weave at the free edge in order to inhibit shrinkage at the free edge, and thereafter appropriately dyeing the tape and thereby differentially shrinking the same so as to make the same concave at the beaded edge, whereby the tape will be straightened when the beaded edge is elongated by clamping fastener elements thereon.

11. In the manufacture of'slide fasteners, the method which includes forming a moderately soft beaded tape edge by laying in two oppositely twisted cords as warp threads adjacent one edge, one cord being laid in on each side of the tape, binding said cords in position by means of a single weft thread, laying extra warp threads ln the web of tape near the free'edge thereof to produce a tight weave at the free edge in order to inhibit shrinkage at the free edge,

and thereafter appropriately dyeing the tape and thereby differentially shrinking the same so as to make the same concave at the beaded edge, and clamping fastener elements on said beaded edge and thereby elongating the same to straight condition.

' GEORGE WINTRISS. 

